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<h2><span class="refentrytitle">Macro BOOST_CONTRACT_ASSERT</span></h2>
<p>BOOST_CONTRACT_ASSERT — Preferred way to assert contract conditions. </p>
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<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2>
<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="reference.html#header.boost.contract.assert_hpp" title="Header &lt;boost/contract/assert.hpp&gt;">boost/contract/assert.hpp</a>&gt;

</span>BOOST_CONTRACT_ASSERT(cond)</pre></div>
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<a name="idm34106"></a><h2>Description</h2>
<p>Any exception thrown from within a contract (preconditions, postconditions, exception guarantees, old value copies at body, class invariants, etc.) is interpreted by this library as a contract failure. Therefore, users can program contract assertions manually throwing an exception when an asserted condition is checked to be <code class="computeroutput">false</code> (this library will then call the appropriate contract failure handler  <code class="computeroutput"><a class="link" href="boost/contract/precondition_failure.html" title="Function precondition_failure">boost::contract::precondition_failure</a></code>, etc.). However, it is preferred to use this macro because it expands to code that throws <code class="computeroutput"><a class="link" href="boost/contract/assertion_failure.html" title="Class assertion_failure">boost::contract::assertion_failure</a></code> with the correct assertion file name (using <code class="computeroutput">__FILE__</code>), line number (using <code class="computeroutput">__LINE__</code>), and asserted condition code so to produce informative error messages (C++11 <code class="computeroutput">__func__</code> is not used here because in most cases it will simply expand to the internal compiler name of the lambda function used to program the contract conditions adding no specificity to the error message).</p>
<p> <code class="computeroutput"><a class="link" href="BOOST_CONTRACT_ASSERT.html" title="Macro BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</a></code>, <code class="computeroutput"><a class="link" href="BOOST_CONTRACT_AS_idm33640.html" title="Macro BOOST_CONTRACT_ASSERT_AUDIT">BOOST_CONTRACT_ASSERT_AUDIT</a></code>, and <code class="computeroutput"><a class="link" href="BOOST_CONTRACT_AS_idm33665.html" title="Macro BOOST_CONTRACT_ASSERT_AXIOM">BOOST_CONTRACT_ASSERT_AXIOM</a></code> are the three assertion levels predefined by this library.</p>
<p><span class="bold"><strong>See Also:</strong></span></p>
<p> <a class="link" href="boost_contract/tutorial.html#boost_contract.tutorial.preconditions" title="Preconditions"> Preconditions</a>,  <a class="link" href="boost_contract/tutorial.html#boost_contract.tutorial.postconditions" title="Postconditions"> Postconditions</a>,  <a class="link" href="boost_contract/tutorial.html#boost_contract.tutorial.exception_guarantees" title="Exception Guarantees"> Exceptions Guarantees</a>,  <a class="link" href="boost_contract/tutorial.html#boost_contract.tutorial.class_invariants" title="Class Invariants"> Class Invariants</a>,  <a class="link" href="boost_contract/extras.html#boost_contract.extras.no_macros__and_no_variadic_macros_" title="No Macros (and No Variadic Macros)"> No Macros</a></p>
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<td><p><span class="term">Parameters:</span></p></td>
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<td><p><span class="term"><code class="computeroutput">cond</code></span></p></td>
<td><p>Boolean contract condition to check. (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <code class="computeroutput">BOOST_CONTRACT_ASSERT((cond))</code> will always work.) </p></td>
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<td align="right"><div class="copyright-footer">Copyright © 2008-2019 Lorenzo Caminiti<p>
        Distributed under the Boost Software License, Version 1.0 (see accompanying
        file LICENSE_1_0.txt or a copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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